1. Field of the Invention
This invention relates to railway vehicles and in particular to pedestal liners for pedestal trucks of such vehicles.
2. Prior Art Statement
It is known in the art to provide a wear member supported by at least one of a pair of relatively movable components of a railway vehicle for the purpose of protecting the components from wear. However, heretofore it has been common practice to provide a wear member made either entirely of a hard metal or entirely of a hard polymeric material and such wear member is suitably supported in position between such components and once the wear member becomes excessively worn it is removed and a new one installed in its position. However, metal wear members are usually made of comparatively expensive metallic materials and do not have optimum antifriction properties while wear members made entirely of polymeric material have comparatively poor structural strength and thus are often easily broken requiring frequent replacement.
It has also been proposed heretofore to provide so-called wear members or liners for center plate structure of a railway vehicle with reinforcing material embedded therein as disclosed in U.S. patent application Ser. No. 841,175, filed Oct. 11, 1977 and which is now U.S. Pat. No. 4,188,888; however, such liners have minimum structural strength and in use are confined between associated supporting surfaces.
Further, it has been proposed in U.S. Pat. No. 3,554,618 to provide a U-shaped pedestal liner consisting of a bight and a pair of parallel legs which has an inserted nylon wear plate for the bight which is unsupported in the central portion of the bight and which is free of antifriction material on the outside surfaces of the parallel legs where substantial wear may also occur in a pedestal liner.
It has also been proposed in U.S. patent application Ser. No. 27,340, filed Apr. 5, 1979, and which is now U.S. Pat. No. 4,238,039, to provide a wear member comprising a support having a continuous planar supporting surface, a polymeric antifriction wear material, and means attaching the polymeric material to the support and supporting same against the continuous supporting surface for the purpose of providing a substantially structurally self-supporting wear member; however, basically in such a member the teaching is to the use of a supported flat planar polymeric antifriction material in a single plane.
In addition, it has been proposed in U.S. patent application Ser. No. 30,035, filed Apr. 13, 1979, and which is now U.S. Pat. No. 4,237,793, to provide a roughly U-shaped pedestal liner having a continuous backing material and a particular antifriction material bonded against both the bight and parallel legs of the backing material.